North Korea has announced the success of its third underground nuclear test.

The country's state-run television said on Tuesday afternoon that the test was carried out safely at a high level, with a warhead that was smaller, lighter and more explosive than those used in past tests.

The report said the test was aimed at ensuring the nation's security and sovereignty in the face of US hostility undermining the North's right to a legal, peaceful satellite launch. [link to www3.nhk.or.jp] .